Abstract: There is disclosed a tool holding construction wherein a tool support such as a turret for an automatic screw machine or the like, is provided and formed with a series of cylindrical openings to receive the shanks of tool members fitting very snugly therein, being normally rotatably adjustable when the machine is being setup by appropriate manipulation, means to clamp said shank being provided, the means themselves being likewise very snugly fitted in the tool support, and the shank hereof being formed to faciliate removal of the tool when rotated to a certain position without requiring the usual extreme measures for such removal.